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Hypothallus
In true slime molds (myxogastria), lichens, and in species of the family Clavicipitaceae, the hypothallus is the layer on which the fruit body sits, lying in contact with the substrate. The word is derived from the Ancient Greek root ''hypó'' ("under") and ''thallós'' ("shoot" or "thallus"). The hypothallus is produced by the plasmodium at the beginning of fructification. Depending on the species, it can be membranous to thick or tender to solid and nearly transparent to brightly coloured. It may surround an individual fruit body, or may form a contiguous connection between multiple fruit bodies. In some rare cases it is missing entirely. In crustose lichens, the hypothallus is the blackish lower layer of the thallus that produces rhizines, which are holdfasts that attach the lichen to its substrate. In some taxa the hypothallus may be involved in the formation of the fruit body. In the "epihypothallic" Stemonitida, the hypothallus forms hollow, tubular stems and a columella ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crustose Lichen
Crustose lichens are lichens that form a crust which strongly adheres to the Substrate (biology), substrate (soil, rock, tree bark, etc.), making separation from the substrate impossible without destruction. The basic structure of crustose lichens consists of a cortex (botany), cortex layer, an algal layer, and a medulla. The upper cortex layer is differentiated and is usually pigmented. The algal layer lies beneath the cortex. The medulla fastens the lichen to the substrate and is made up of Fungus, fungal hyphae. The surface of crustose lichens is characterized by branching cracks that periodically close in response to climatic variations such as alternate wetting and drying regimes. Subtypes * Powdery – considered as the simplest subtype due to the absence of an organized thallus. :The thallus appears powdery. :E.g. Genera ''Lepraria'', ''Vezdaea'' * Endolithic – grows inside the rock, usually in interstitial spaces between mineral grains. The :upper cortex is usually d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lichen
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Introduction to Lichens – An Alliance between Kingdoms . University of California Museum of Paleontology. Lichens have properties different from those of their component organisms. They come in many colors, sizes, and forms and are sometimes plant-like, but are not s. They may have tiny, leafless branches (); flat leaf-like structures ( |
Tubifera Ferruginosa II 258341770
''Tubifera'' is a genus of slime moulds from the subclass Myxogastria. The genus comprises 12 species. Description The fruit-bodies are aethalia formed from numerous, usually densely packed sporangia. The oblong sporangia are ochre, pink or red to dark brown and may be shiny or shimmering. They open at the tip to release the spores. The hypothallus is spongy, occasionally raised to a stem-like, stock, dark-coloured structure or also, on ''Tubifera bombarda'', soft and film-like thin. The membranous, single layered peridium outlasts the below half. A pseudocapillitium may or may not be present. The spores are light yellow to reddish-brown. Habitat '' Tubifera ferruginosa'' and '' Tubifera microsperma'' are more widespread and common than the other species from this genus. All species, except ''Tubifera casparyii'', are also common in the tropics. Classification The genus was circumscribed in 1873 by Józef Thomasz Rostafiński. The type species is ''Tubifera ferruginosa'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myxogastria
Myxogastria/Myxogastrea (myxogastrids, International Code of Zoological Nomenclature, ICZN) or Myxomycetes (International Code of Nomenclature for algae, fungi, and plants, ICN), is a Class (biology), class of slime molds that contains 5 order (biology), orders, 14 family (biology), families, 62 genera, and 888 species. They are colloquially known as the ''plasmodial'' or ''acellular'' slime moulds. All species pass through several, very different morphology (biology), morphologic phases, such as microscopic individual cells, slimy amorphous organisms visible with the naked eye and conspicuously shaped fruit body, fruit bodies. Although they are monocellular, they can reach immense widths and weights: in extreme cases they can be up to across and weigh up to . The class Myxogastria is distributed worldwide, but it is more common in temperate regions where it has a higher biodiversity than in polar regions, the subtropics or tropics. They are mainly found in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clavicipitaceae
The Clavicipitaceae are a family of fungi within the order Hypocreales. A 2008 estimate placed 43 genera in the family, but recent work has increased this number to 97. Phylogeny Molecular phylogenetic analysis of multigene DNA sequence data indicates the taxon Clavicipitaceae is paraphyletic, and consists of three well-defined clades, at least one of which is shared with members of another fungal family (Hypocreaceae). The evolution within the Clavicipitaceae is marked by interkingdom host jumping, and the range of this large and heterogeneous fungal group spans mutualistic plant symbionts, as well as parasites of plants, insects, and other fungi. Significance Many of its members produce alkaloids toxic to animals and humans. One of its most infamous species is ''Claviceps purpurea'', which has historical significance as the cause of St. Anthony's fire, also known as ergotism. Ergotism is caused by ergot alkaloids, such as ergotamine and ergocristine, which are chemical d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic period (), and the Classical period (). Ancient Greek was the language of Homer and of fifth-century Athenian historians, playwrights, and philosophers. It has contributed many words to English vocabulary and has been a standard subject of study in educational institutions of the Western world since the Renaissance. This article primarily contains information about the Epic and Classical periods of the language. From the Hellenistic period (), Ancient Greek was followed by Koine Greek, which is regarded as a separate historical stage, although its earliest form closely resembles Attic Greek and its latest form approaches Medieval Greek. There were several regional dialects of Ancient Greek, of which Attic Greek developed into Koine. Dia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thallus
Thallus (plural: thalli), from Latinized Greek (), meaning "a green shoot" or "twig", is the vegetative tissue of some organisms in diverse groups such as algae, fungi, some liverworts, lichens, and the Myxogastria. Many of these organisms were previously known as the thallophytes, a polyphyletic group of distantly related organisms. An organism or structure resembling a thallus is called thalloid, thallodal, thalliform, thalline, or thallose. A thallus usually names the entire body of a multicellular non-moving organism in which there is no organization of the tissues into organs. Even though thalli do not have organized and distinct parts (leaves, roots, and stems) as do the vascular plants, they may have analogous structures that resemble their vascular "equivalents". The analogous structures have similar function or macroscopic structure, but different microscopic structure; for example, no thallus has vascular tissue. In exceptional cases such as the Lemnoideae, where ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasmodium (life Cycle)
A plasmodium is a living structure of cytoplasm that contains many nuclei, rather than being divided into individual cells each with a single nucleus. Plasmodia are best known from slime molds, but are also found in parasitic Myxosporea, and some algae such as the Chlorarachniophyta. Structure A plasmodium is an amoeboid, multinucleate, and naked mass of cytoplasm that contains many diploid nuclei. The resulting structure, a coenocyte, is created by many nuclear divisions without the process of cytokinesis, which in other organisms pulls newlydivided cells apart. In some cases, the resulting structure is a syncytium, created by the fusion of cells after division. Under suitable conditions, plasmodia differentiates and forms fruiting bodies bearing spores at their tips. Taxonomic distribution The term plasmodium, introduced by Leon Cienkowski, usually refers to the feeding stage of slime molds; these are macroscopic mycetozoans. The multinucleate developmental stages of so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fructification
Fructification () are the generative parts of the plant (flower and fruit) (as opposed to its vegetative parts: trunk, roots and leaves). Sometimes it is applied more broadly to the generative parts of gymnosperms, ferns, horsetails, and lycophytes, though they produce neither fruit nor flower. Since the works of Andrea Caesalpino (1519–1603) the characters of fructification have been extensively used as a basis for the scientific classification of plants. Carl Linnaeus (1707–1778) raised the description of the parts of fructification to an unprecedented level of precision. He insisted that genera and the higher groups of plants must be characterised in terms of the fructification alone without using vegetative parts (which can be used only to characterise the species within genera). At that time it was believed that all plants have flowers and fruits. It was not until the nineteenth century that the important difference between seeds and spores was recognised and the use of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slime Mold
Slime mold or slime mould is an informal name given to several kinds of unrelated eukaryotic organisms with a life cycle that includes a free-living single-celled stage and the formation of spores. Spores are often produced in macroscopic multicellular or multinucleate fruiting bodies which may be formed through aggregation or fusion. Slime molds were formerly classified as fungi but are no longer considered part of that kingdom. Although not forming a single monophyletic clade, they are grouped within the paraphyletic group Protista. More than 900 species of slime mold occur globally. Their common name refers to part of some of these organisms' life cycles where they can appear as gelatinous "slime". This is mostly seen with the Myxogastria, which are the only macroscopic slime molds. Most slime molds are smaller than a few centimetres, but some species may reach sizes up to several square metres and masses up to 20 kilograms. They feed on microorganisms that live in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhizine
In lichens, rhizines are multicellular root-like structures, arising mostly from the lower surface. A lichen with rhizines is termed rhizinate, while a lichen lacking rhizines is termed erhizinate. Rhizines serve only to anchor the lichen to their substrate; they do not absorb nutrients as do plant roots. Characteristics of the rhizines are used to identify lichens, for example: whether they are dense or sparse, whether they are uniformly distributed or clumped in specific areas, and whether they are straight or branched. Only foliose lichens may possess rhizines, not crustose or fruticose lichens, which lack a lower cortex. Rhizohyphae are a type of attachment structure on some lichens. Rhizohyphae are more slender than rhizines and are one cell thick in diameter. Rhizohyphae often occur as a felt-like hyphal mass. See also *Rhizoid Rhizoids are protuberances that extend from the lower epidermal cells of bryophytes and algae. They are similar in structure and function to the ro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holdfast (biology)
A holdfast is a root-like structure that anchors aquatic sessile organisms, such as seaweed, other sessile algae, stalked crinoids, benthic cnidarians, and sponges, to the substrate. Holdfasts vary in shape and form depending on both the species and the substrate type. The holdfasts of organisms that live in muddy substrates often have complex tangles of root-like growths. These projections are called haptera and similar structures of the same name are found on lichens. The holdfasts of organisms that live in sandy substrates are bulb-like and very flexible, such as those of sea pens, thus permitting the organism to pull the entire body into the substrate when the holdfast is contracted. The holdfasts of organisms that live on smooth surfaces (such as the surface of a boulder) have flattened bases which adhere to the surface. The organism derives no nutrition from this intimate contact with the substrate, as the process of liberating nutrients from the substrate requires ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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